The invention relates to a method of making a rear shelf trim panel with speaker apertures to accommodate a speaker mounted under the rear shelf trim panel.
Many motor vehicles now have FM stereo radios or more elaborate sound systems such as tape players, compact disc players digital tape, and computer sound systems with accompanying speakers for the enjoyment of the driver and passengers. Furthermore, the electronics of the sound system have also greatly improved. As a result of all these improvements, the sound emanating from a car stereo speaker has a quality that was unheard of only a few years ago.
Many after-market speakers are free standing with their own cases and speaker grills. The speaker grill is commonly used to conceal and protect the actual speaker cone against puncture or other damage. Factory mounted speakers are often mounted in concealed places such as behind door panels and under rear trim shelf panels. When the speakers are positioned behind or under such panels, the panels must incorporate a speaker grill that has apertures and cutouts to reduce muffling effects of the panels and to promote the efficiency of sound emanating from the concealed speakers into the interior of the motor vehicle.
Many known speaker grills are molded. Pins are used in the mold to form apertures through the cover to allow sound emanation. A porous cloth or non-woven fabric may provide a fabric covering for the speaker grill. While the panel needs holes to allow transmission of sound, a light porous cloth or fabric may cover the holes in the panel structure without an overly undesirable amount of sound blockage.
What is needed is an expeditious method of forming an integrated speaker grill with an automotive interior panel that has apertures incorporated therein to provide for the transmission of sound from the speaker into the automotive vehicle interior.
In accordance with one aspect of the invention, a process for forming a combined speaker grill and automotive interior trim panel includes the initial step of providing a substrate layer of a heated mat material having a content of thermoplastic material such that it is moldable under heated conditions. Preferably the mat also has a content of flax fiber. The process also includes punching a plurality of apertures in a speaker grill section of the heated substrate. The punching of the apertures is, in one embodiment; simultaneous with the molding step such that the apertures are formed through both the substrate and the decorative layer as the substrate and decorative layer are shaped into the final panel contour.
A decorative layer is provided onto the heated substrate. The decorative layer is preferably a porous carpet with a thermal plastic back surface.
The substrate and the decorative layer are molded into the desired shaped panel such as a rear shelf trim panel such that said apertures form an integrated speaker grill section within the panel.
Preferably, a first and second mold dies form the apertures in the substrate. The first mold die has apertures therein and the second mold die has a punch set that fits in the apertures of the first mold die to punch apertures through both the decorative layer and the substrate as the mold dies are closed to shape the substrate and the decorative layers into the panel.
In one embodiment, the apertures in the substrate are formed in the speaker grill section before the substrate is molded into its final shape. The grill section is positioned such that pins are then received in the apertures in the grill section and the decorative layer is positioned over the substrate, grill section and the pins in the mold. The mold is closed and the substrate layer, grill section and decorative layer are molded into a shape of an automotive interior panel under pressure.
In one embodiment, the speaker grill section is a separate previously formed perforated member that is placed over an opening of the substrate layer such that a peripheral edge of the perforated grill section overlaps an edge of the substrate layer about the opening. A hot melt adhesive is applied to the perforated grill section for adhesion to the decorative layer.
The substrate is then removed from the pins and mold. The apertures in the grill section are positioned under the decorative layer, i.e., the molded panel has the decorative layer spanning over the apertures in the grill section of the substrate.
Preferably, the pins extend through a first mold die and are level with an interior surface of the first mold die. The apertures in the substrate are formed by a first punch set aligned with the pins to push through the substrate and recess the pins. The punch set is then raised to remove the punched scraps of substrate. The pins are then raised to intrude into the apertures in the substrate. A second mold die that complements the first mold die is provided and the panel is molded into shape with the pins extending through the first mold die and remaining in the apertures in the substrate.
In accordance with another aspect of the invention, a process for forming a combined speaker grill and automotive interior trim panel is characterized by the steps of providing a decorative layer that is capable of being bonded to the substrate layer; placing the heated substrate layer and decorative layer into an open mold; closing the mold and molding the substrate layer and the decorative layer into a formed automotive interior panel under pressure between two closed mold dies with a first mold die section having a section with a plurality of holes therein and a complementary mold die section having a plurality of punches that mate with the plurality of holes to punch a plurality of apertures in the formed panel to form an integral speaker grill with the panel; and opening the mold dies and cooling the panel to be resolidified with the substrate and decorative layers being bonded together and removing the molded formed panel and speaker grill from the mold.
In accordance with another aspect of the invention, a process for forming a combined speaker grill and automotive interior trim panel is characterized by the steps of: providing a grill section and substrate layer of a heated mat material having a content of thermoplastic material such that it is moldable under heated conditions; punches out a plurality of apertures in the grill section; positioning said grill section such that a pin is received in each respective aperture with an end of the pin substantially coplanar with one side of the grill section; providing a decorative layer that is capable of being bonded to the substrate layer and said grill section; molding the substrate layer, grill section, and the decorative layer into a formed automotive interior panel under pressure between two closed mold dies with the decorative layer spanning over the pins in the apertures in the substrate to form an integrated speaker grill with the panel; removing the molded formed panel and speaker grill after the thermoplastic material in the panel is cooled to allow the panel to be resolidified and the substrate and decorative layers to be bonded together.
In accordance with another aspect of the invention, a process for forming a combined speaker grill and automotive interior trim panel is characterized by the steps of: providing a substrate layer of a heated mat material having a content of thermoplastic material such that it is moldable under heated conditions; providing an aperture in the substrate layers; that is slightly smaller than the grill section; placing a perforated grill section over the opening in the substrate with the respective edges overlapping; positioning a pin in each respective hole in the grill section with an end of the pin substantially coplanar with one side of the grill section; providing a decorative layer that is capable of being bonded to the substrate layer and grill section; molding the substrate layer grill section and the decorative layer into a formed automotive interior panel under pressure between two closed mold dies with the decorative layer spanning over the pins in the apertures in the substrate to form a integral speaker grill with the panel leaving an edge of the substrate layer uncovered; and punching out an additional grill section with a plurality of holes; removing the molded formed panel and speaker grill after the thermoplastic material in the panel is cooled to allow the panel to be resolidified and the substrate and decorative layers to be bonded together; and removing the punched out additional grill section for placement in an aperture of an another substrate layer.
In accordance with another aspect of the invention, a molded interior automotive panel and speaker grill combination includes a molded substrate layer having thermal plastic content and a flax fiber content. A plurality of apertures through the substrate are aligned with a speaker-mounted there behind. A decorative layer is bonded on top of the substrate material and molded thereto. In one embodiment, the decorative layer is a porous carpet layer that spans over the plurality of apertures. In another embodiment, the decorative layer also has apertures therethrough that align with the apertures in the substrate. In another embodiment, a separate grill section is received over an opening through the substrate. Both the grill section and substrate are made from the same material. The grill is then bonded to the substrate about the aperture with the carpet layer spanning over both the grill section and substrate.
In accordance with another aspect of the invention, a method of manufacturing a structurally supportive automotive interior trim panel includes the steps of; providing a porous substrate of a heated mat material having a content of organic fiber and thermoplastic material such that it is moldable; applying a non-porous thermoplastic film layer onto the layer of heated substrate layer; and folding said substrate and film layers generally in half into a set of upper layers and lower layers into a mold with first and second dies, at least one blow pin is interposed between the two inner layers of the folded film. The mold is then closed onto the substrate to provide a perimeter seal such that said film layer form an interior bladder surrounded by the substrate. The automotive interior trim panel is blow molded by applying gaseous medium through the at least one blow pin to expand the film layers and substrate outward against outer contour surfaces of the mold. The formed automotive interior trim panel is then cooled cooled to a rigid state the panel is the demolded from the mold.
Preferably a decorative layer is positioned in the first mold die before placing the folded substrate and film layers thereon such that the automotive trim panel has an exposed decorative outer layer after molding of the substrate with the decorative layer.
It is also preferable that sound absorbing material is placed in a second mold die such that the automotive trim panel has an opposing surface of sound absorbing material bonded to the substrate opposing the exposed decorative outer layer. If needed, attachment brackets are placed therein for bonding to the substrate.
It is desirable that before blow molding, a plurality of apertures are punched in the heated substrate to form a grill section. In one embodiment, an opening is formed in the lower layers of the substrate and film which corresponds to lie under the grill section. The mold dies provide an inner perimeter seal about the grill section of the opening. The punching of the apertures in the grill section is simultaneous with the blow molding step such that said apertures are formed through said decorative layer and said upper layers of said substrate and film.
In yet another embodiment the apertures are formed in the grill section before the substrate is molded into its final shape. Pins are positioned in the apertures after the apertures are formed. The decorative layer is then placed over the substrate, grill section, and the pins in a mold and the assembly is then blow molded together.
The pins are extended through a first mold die and positioned to align with the interior surface of the mold. The apertures are punched by a first punch set aligned with said pins to push through said substrate and recess the pins. The punch set is raised to remove the punched scraps of substrate and the pins are lifted to intrude into the apertures in the grill section of the substrate before folding of the substrate onto itself. An enlarged opening is punched in another layer of the substrate that is aligned with the grill section when said substrate is folded onto itself before the blow molding of the trim panel.
In this fashion structurally supporting automotive trim panel is molded either by pressure or by blow molding and can integrate speaker grill section and structurally supporting brackets in an expeditious time saving fashion.